Voice warning systems



SPEAKER Aug. 27, 1957 HEADPHoNr-.s

v. B. HART 2,804,501

VOICE WARNING SYSTEMS Filed Sept. 26. 1955 DETECTOR.

IQ d) O d N e :V: -hl' LL! 1 D CO N 4 f 9 x $9( 1 |||I INVENToR.

BY VICTOR B HAR-T @fwn/@M fm ATTORNEYS VoLTAne -I- nited States Patent C) VQICE WARNING SYSTEMS Victor B. Hart, Seattle, Wash., assignor to Boeing Airplane Company, Seattle, Wash., a corporation of Delaware Application September 26, 1955, Serial No. 536,410

15 Claims. (Cl. 179-5) This invention relates to a voice warning system or the like and more particularly to an emergency warning system for use in airplanes and similar applications. In the disclosed form of the invention, constituting `the presently preferred form thereof, voice warning messages tak-en from recordings are injected into the intercommunication system of the airplane automaticallyin response to any -of different emergency conditions requiring attention bythe personnel, and in `accordance with an important feature ofthe novel system warning messages of high priority or importance are enunciated to the exclusion of messages of lower relative priority which might then otherwise be transmitted due to concurrent emergency conditions. Still another feature of the novel system is the provision of volume control means by which warning messages are automatically annunciated in the intercommunication system at a volume level insuring notice thereof, but which may be reduced to a background level at will thereafter to permit necessary usage of the intercommunication system Vfor coordination between crew members. While the invention is herein disclosed in its presently preferred form it will be recognized that with respect to certain features and details of the disclosure changes and modifications may be made within the scope of the invention.

There are any number of dilerent emergency conditions of varying importance that may occur in an yairplane and which require notice or action by the pilot or other crew members. Some of these include `failure of a landing gear-to retract or to lower, failure of the 4electrical system or a portion thereof, re, failure of the flaps to project or retract, loss of Vcabin pressure, ete. Conventional warning systems using lliash'ing lights or different types of Sounders, including buzzers, horns, etc. It is found in many cases that conventional methods of alerting airplane crew members to different emergency conditions are unreliable and inadequate. A signal light on an instrument panel, for example, can easily be overlooked when other matters require close concentration. On the other hand, signal lights which are suiciently bright to attract attention can be a hazard, especially when ilying at night. Audible yalarms of the .conventional type can also be disregarded vby a busy pilot or crew member unless the noise is so great as to constitute `a distraction, and there are even instances of the noise source being removed subconsciously without notice being taken of lthe message which it was intended -to convey. Another di'icul'ty with both conventional types of warning systems is the difficulty often experienced of identifying the particular warning condition intended to be represented by the llashing light or by the audible sound. For example, if a different number of light flashes or horn soundings are used to represent different emergency conditions that may develop, according to a code, it is entirely possible for the personnel, especially under `the pressure of an emergency, to forget the code and act on an erroneous interpreta-tion of the signal.

A general object of the present invention is an emere ice gency warning system which satisfactorily overcomes the `above-mentioned diiliculties.

Another object of the present invention is such an emergency warning system which is certain -to alert the appropriate personnel and at the same time delivers a clearly audible and unmistakable warning message representing any particular emergency condition.

Another yobject is the provision of van effective and practicable emergency Warning system by which dissemination of worning signals to dilerent parts of the airplane, i. e. lthose served by the intercommunication system, is conveniently possible. A related object is such a warning .system producing warning message signals which may be entered into the intercommunication sys- .tem of the airplane without interfering with the normal usage of the latter system, except in brief intervals during which warning messages are first transmitted over the system for the alerting of personnel.

The above and other features, objects and advantages of the invention, including cert-ain details of the preferred form thereof will become evident from the following description by reference to the accompanying drawings. The drawing constitutents a schematic diagram of the preferred form of the invention comprising an integral part of an intercommunication system such as that found in airplanes. It will be recognized, however, that the principles of the invention lare applicable to other vehicles and even to iixed installations, and that the particular Vcontrol conditions causing the transmission of messages, or more broadly the delivery of information representing different control conditions, may vary.

Referring to Ithe drawing, the illustrated system is provided with N different warning condition detectors 10 which are constructed and arranged in the airplane to sense the occurrence of that many different emergency conditions to be annunciated in the intercommunica-tion system. These individual detectors 10 are assigned alphabetical letters serially in the diagram corresponding lto the predetermined order of priority or importance of the emergency conditions to which they are respectively responsive. Thus the detector A is that which corresponds to the most serious of all emergency conditions, to which the airplane personnel must be alerted. Detector B corresponds to .the second most serious emergency conditions, whereas the last or lowest-order detector N represents the least serious condition in the particular installation.

I-n the illustration the detectors 10 are not shown in detail. They may comprise any of different types of devices, conventional or otherwise, for detecting dierent Vcontrol conditions for operating the message reproducer. Thedetectors 10 include normally open electrical switches the contacts of which (not specifically shown) are connected in series with the respective control relays 12A, 12B, etc. Each such control relay and detector switch connected in series therewith is arranged to be impressed with voltage from the voltage supply 14, as shown. In the normally deenergized condition of all control relays any such relay is energizable directly from the source 14 merely by actuation of the associated detector 10. However, the coil of control relay 12B is connected to receive its energizing current through the normally closed contacts e of control relay 12A. Likewise, the energizing circuit for the coil of relay 10C extends through the normally closed contacts e of both control relays 12A and 12B. In similar fashion, the energizing circuit for the last control relay 10N in the series must receive its energizing current through the normally closed contacts e of all of the other control relays in the series. The effect of this arrangement is that energization of any control relay in the series is permitted only when no other control 'relay of higherpriority is then energized.` By the same token if during actuation of any control relay there occurs an emergency condition which causes actuation of a control relay of relatively higher priority in the series, then the first will automatically become deenergized. Energization of any control relay, producing closure of its contacts f, forms an energizing circuit for the interphone relay 16 from the voltage supply 14. Actuation of relay 16 connects the output of the local amplifier 1S to the input of the amplifier of the intercommunication system of the airplane or other installation, as illustrated. The local amplitier 18 is continuously in readiness for the transmission of a voice warning message representing any of the different emergency conditions sensed by the detectors, as will become evident.

The required emergency voice warning messages are recorded in suitable reproduction apparatus operable to repeatedly deliver any such message in the form of voice electric signals applied to the local amplifier 18. ln the illustration, which is greatly simplified and primarily schematic in form, the individual warning messages are borne by the endless magnetic tapes 20A, 20B, 20N, rencircling the idler drum 22 and the powered drum 24. Suitable pick-ups 26A, 26B', 26N, arranged in cooperative relation to the individual tapes, perform the transducing function by which the recorded speech messages are converted into electric signals. Closure of contacts b of any control relay 12 applies the output signals from the corresponding pick-up 26 to the input of amplifier 18 through one of the associated pick-up conductors 28.

The powered drum 24 is driven by a suitable motor and gear transmission 30. Such motor is energized through conductor 32 and the normally closed contacts a of cam-actuated switch 34 whenever an emergency condition develops. This energizing circuit for the motor 30 4is formed between the negative terminal and the positive terminal of the voltage supply 14 through the contacts d of any control relay 12 energized by the associated emergency condition detector so that as long as the emergency condition persists an energizing circuit for the motor 30 is available through contacts a of a switch 34. However, once the motor starts to rotate the drum 24 to reproduce a particular voice warning message the cam follower 36 connected to switch 34 moves from the valley or notch vof cam 38 to the raised land thereof where it remains for the remainder of the rotation cycle of the cam, which begins and ends with the initiation and termination of the individual recordings on the tapes A, 20B, etc. During the time the cam follower 36 rides on the land of the cam 38, switch 34 is reversed in position, to form an energizing circuit in the nature of a holding circuit for motor through the contacts b of the switch from the voltage supply 14. This insures completion of the reproduction of an emergency warning message cycle once the cycle is started. The gearing 40 by which the cam 38 is rotated synchronously with the drum 34 insures that the timing of cam rotation and also that the cycle duration of cam rotation corresponds to the timing and cycle duration of the plurality of individual voice message records 20. Thus as long as an emergency condition persists which produces actuation of any control relay 12A, 12B, etc., the recorded warning message carried by the corresponding magnetic tape 20A, 2GB, etc., is reproduced repeatedly by continuing operation of the drive motor 30. If the emergency condition should terminate at any instant between the beginning and end of the message reproduction cycle, the vcycling cam 38, acting through switch 34, insures that the particular message will be completed before the motor 30 is deenergized.

This message completion feature is important, particularly in cases of intermittent fault conditions which are of suticient importance to require alerting the crew to their existence, but which do not persist for a length of time equal to the period required for reproducing a full voice message describing Aor representing the particular condi- Cil , 4 tion. However, should a condition of higher priority develop during the reproduction of an emergency warning message of relatively lower priority, the latter message will be interrupted immediately and the higher priority message commenced. While arrangements may be made even then to permit completion of the relatively low priority message before the higher-priority message can supersede it, it is preferred to interrupt the latter at an intermediate point because it is believed that the startling effect of interrupting one warning message in order to deliver another message of greater importance will have a particularly startling and personnel-alerting effect so essential to meet certain important emergencies without delay. Y

The local amplifier 18 in which the electric signals representing the different emergency warning messages are amplified for applicaton to the interphone or intercommunication system of the airplane has a selective volume control circuit of any suitable form which, in the example, includes the two alternatively selected volume control resistances 42 and 44 in the form of potentiometers. A volume control relay 46 selects one or the other of these variable resistance elements to change the amplification of signals in amplifier 18.` This relay is normally deenergized and in that condition the resistance element 42 is connected to the amplifier 18 through the normally closed contacts a of the relay. Under these conditions the amplifier has maximum gain, and by proper adjustment of resistance 42 delivers the voice warning signals to the interphone system at a volume level preferably materially above the level of normal live voice communications over the system so that the warning message will immediately come to the attention of all personnel. One or more call channel release switches 48 are provided,

r .which may be actuated at will to form an energizing circuit for the relay 46 through the closed contacts d of any control relay 12 which is then actuated by the existence of an associated emergency condition. The instant relay 46 is actuated by closure of one of the switches 48, a holding circuit is formed through its contacts d, and it remains actuated although the switch 48 may be released. Actuation of relay 46 connects the resistance element 44 in the circuit of amplifier 18 and reduces materially the gain of amplifier 18 so that the electric signals representving the recorded voice messages reach the interphone amplifier preferably at an audible level below normal live voice conversation level in the interphone system.

The holding circuit through contacts d of relay 46 is instantly broken when the particular control relay 12 .then energized becomes deenergized. This may occur, of course, upon termination of the emergency condition causing actuation of the particular control relay. On the other hand, it may also occur in the short transitional period between deactuation of such control relay by energization of another control relay of relatively higher priority, and the completion of actuation of the latter or high-priority relay. In this short interim period, i. e. between opening of the contacts d of the relatively lowpriority relay and closure of the corresponding contacts d of. the relatively high-priority relay, the cessation of energizing current in relay 46 is such that the latter releases its contacts and breaks its own holding circuit which existed through its Contact d. As a result the occurrence of an emergency condition of relatively high priority during the existence of an emergency condition of lower priority automatically restores the amplifier 18 to its high-gain setting for purposes of initial annuncia- ,tion of the high-priority message 'at a high sound level.

The nature of the voice warning messages carried by .the record tapes 20A, 20B, etc., will, of course, be dependent upon the usage to which the system is adapted. In the case of airplane emergency warning applications it is preferred that each recorded warning message include a concise description of the nature of the emergency condition, followed by concise instructions for eliminating, avoiding or otherwise responding to the emergency condition. For instance, a typical voice warning message recorded on one of the tapes 20 could be as follows: Right Landing Gear Not Lowered. Raise Flaps and Clim Suitable actuating apparatus responsive to the combined conditions of the left landing gear becoming lowered and failure of the right landing gear to lower also would, of course, in that situation operate an appropriate detector in order to cause the reproduction of such a voice Warning message in the interphone system. Many other and dilerent types of emergency warning messages or other instructional or informational messages corresponding to different control conditions developing in the particular application of the invention, whether of an emergency nature or otherwise, may also be annunciated by such a system.

In operation of the system, when an emergency or other control condition develops which actuates one of the detectors 10, the corresponding relay 12 associated therewith is energized, causing closure of contacts b, d and f of such relay. Contacts b connect the associated voice reproducer pick-up 26 to the input of local amplier 18. Contacts d form an energizing circuit for `the motor 30 through the normally closed contacts a of switch 34 and also partially form but do not complete an energizing circuit for relay 46. Closure of contacts f energize the interphone call relay 16 to connect the ampliiier 18 to the interphone amplifier for delivering the reproduced voice message signals to the interphone system. As the motor 30 rotates the record tape drum 24 to reproduce the recorded voice message of the selected pick-up 26 and associated tape 20, the cam-actuated switch 34 is reversed by the cam 38 to form a holding icircuit for continuing energization of motor 30 insuring Ithat the message cycle will be completed before the motor 30 can become deenergized.

Because resistance element 42 is connected in the gain control circuit of amplifier 18, the latter has maximum gain and the emergency warning signal is applied to the interphone circuits initially at an amplitude level insuring that it will be heard by all concerned. The audio level of the reproduced voice warning message may be reduced at will by pressing on one of the [call channel release switches 4S to energize the relay 46 and connect the gain control potentiometer 44 in the Vamplifier circuit for reducing the gain of the latter to a level such that the message may still be heard yet normal conversation may be carried on over the interphone system.

Upon completion of the recorded Voice warning message the cam follower 36 again drops into the notch of cam 38 to close contacts a of switch 34. The motor becomes deenergized at that time unless the emergency condition still exists and maintains the particular control relay 12 in the energized condition, thereby to initiate another reproduction cycle in which the same warning message is repeated into the system.

If during the existence of a control or emergency condition of relatively low priority there develops a condition of relatively high priority, the resultant actuation of the associated control relay 12 corresponding to the high-priority condition opens its contactse thus breaking the energizing circuit for the previously energized control relay of lower priority. The more important message, therefore, automatically supersedes the less important message. During the transition relay 46 becomes deenergized so that the message of relatively high importance is 'injected initially at relativelyV high volume level into the interphone system.

The foregoing description applies primarily to the preferred and illustrated form of the invention. As previously stated herein, those skilled in the art will recognize that the inventive principles are not necessarily limited in their application to the present basis of illustration.

I claim as my invention:

l. In combination with a vehicle, a voice communication system therein, the combination comprising transducer means for converting voice electric signals into audible speech sounds, electric circuit means energizingly connected to said transducer means for application thereto of voice electric signals, means connected for impressing live voice communication electric signals on said circuit means to operate said transducer means, and emergency warning means including speech reproducing means having a recorded-voice pick-up element operable for translating an emergency warning speech record into corresponding voice electric signals, said pick-up element being operatively connected to said transducer means and adapted for applying recorded emergency speech electric signals to said transducer means simultaneously with application thereto of said live voice electric signals,

and means selectively actuatable by a predetermined emergency condition and operatively connected to said reproducing means for automatically operating said reproducing means selectively in response to such predeternrined emergency condition for applying recorded lemergency speech signals to said transducer means.

2. In a vehicle, a voice communication system, comprising transducer means for converting voice electric signals, into audible speech sounds, electric circuit means energizingly connected to said transducer means for application thereto of voice electric signals, means for impressing live voice communication electric signals on said circuit means to operate said transducer means, and emergency warning means including speech reproducing means selectively operable for converting into voice electric signals any of a plurality of recorded emergency condition warning speeches for application thereof to said transducer means, a plurality of emergency condition detecting elements individually and operatively connected to said speech reproducing means, said detecting elements being individually responsive to different emergency conditions represented by the respective recorded warning speeches for selectively operating said reproducing means automatically in response to any such emergency condition to reproduce the corresponding recorded emergency condition warning speech.

3. An emergency condition audible warning system Y for airplanes comprising a transducer from voice electric signals into audible speech sounds, recorded speech reproducing means having a plurality of dierent separate emergency condition warning speech records and selectively operable to convert any of said warning speech records into corresponding electric signals applied to said latter transducer for audible reproduction thereof, a plurality of different emergency condition detecting elements operatively arranged in the airplane for actuation thereof automatically by occurrence of different emergency condiitons verbally represented by said warning speech records respectively, and coordinating means controlled by said detecting elements individually for selectively operating said reproducing means to reproduce any of said recorded speeches automatically in response to actuation of the corresponding emergency condition detecting element, said different emergency conditions having a predetermined priority arrangement of relative importance, said coordinating means including a plurality of disabling elements respectively associated with the different emergency condition detecting elernents below first priority in said arrangement, each of said disabling elements being controlled by actuation of any detecting element of relatively higher priority for automatically preventing selective operation of said reproducing means to reproduce a warning speech of relatively lower priority than said high-priority detecting element, whereby only the warning speech representing the existing emergency condition of highest priority is reproduced.

4. vThe airplane emergency condition warning system `detned in claim 3, wherein the reproducing means operates through repeating cycles during continued actuation of an emergency condition detecting element.

A5. The airplane emergency condition warning system dened in claim 4, and means controlling the reproducing means and operated by initiation of an operating cycle of said reproducing means to prevent deactuatin of the active emergency condition detecting element from terminating operation of said reproducing means until completion of said initiated cycle.

6. An emergency condition audible warning system for airplanes, comprising, in combination with an airplane interphone system including a transducer from live voice sounds to corresponding electric signals, a transducer from such electric signals into audible speech sounds, and circuit means interconnecting said two transducers, recorded speech reproducing means having a plurality of different separate emergency condition warning speech records and selectively operable to convert any of said warning speech records into corresponding electric signals, said reproducing means being connected to said circuit means for mixing said recorded speech signals with live voice signals simultaneously occurring therein, for application to said latter transducer for audible reproduction thereof, a plurality of different emergency condition detecting elements operatively arranged in the airplane for actuation thereof automatically by occurrence of different emergency conditions verbally represented by said warning speech records respectively, and coordinating means controlled by said detecting elements individually for selectively operating said reproducing means to reproduce any of said recorded speeches automatically in response to actuation of the corresponding emergency condition detecting element.

7. In a vehicle, a voice communication system comprising transducer means for converting voice electric signals into audible speech sounds, electric circuit means energizingly connected to said transducer means for application thereto of voice electric signals, means for impressing live voice communication electric signals on said circuit means to operate said transducer means, and emergency warning means including speech reproducing means selectively operable for converting into voice electric signals any of a plurality of recorded emergency condition warning speeches for application thereof to said transducer means, a plurality of emergency conditions detecting elements individually and operatively connected to said speech reproducing means, said detecting elements being individually responsive to different emergency conditions represented by the respective recorded warning speeches for selectively operating said reproducing means automatically in response to any such emergency condition to repro-duce the corresponding recorded emergency condition warning speech, and means actuatable at will to reduce the amplitudes of said recorded speech electric signals to amplitudes materially below those of normal voice signals in said circuit.

8. A vehicle voice communication system comprising transducer means for converting voice electric signals into audible speech sounds, electric circuit means energizingly connected to said transducer means for application thereto of voice electric signals, means for impressing live voice communication electric si-gnals on said circuit means to operate said transducer means, and emergency warning means including speech reproducing means having a recorded-voice pick-up element operable for translating an emergency warning speech record into corresponding voi-ce electric signals, said pick-up element being operatively connected to said transducer means and adapted for applying recorded emergency speech electric signals to said transducer means of amplitudes materially exceedingV the amplitudes of normal live voice signals in said circuit, means selectively actuatable by a predetermined emergency condition and operatively connected to said reproducing means for automatically operating said reproducing means selectively in response to such predetermined emergency condition for applying recorded emergency speech signals to said transducer means, and means actuatable at will to reduce the amplitudes of said recorded speech electric signals to amplitudes materially below those of normal voice signals in said circuit. I 9. An emergency condition audible warning system for airplanes comprising, in combination With an airplane interphone systemincluding a transducer to connect from live voice sounds to corresponding electric signals, and a transducer from such electric signals into audible speech sounds, recorded speech reproducing means having a plurality of diterent separate emergency condition warning speech records and selectively opcrable to convert any of said warning speech records into corresponding electric signals applied to said latter .transducer for audible reproduction thereof at a predetermined volume level materially above normal live voice volume in said transducer, a plurality of dilerent emergency condition detecting elements operatively arranged in the airplane for actuation thereof automatically by` occurrence of different emergency conditions verbally represented by said warning speech records respectively, coordinating means controlled by said detecting elements individually for selectively operating said reproducing means to reproduce any of said recorded speeches automatically in response to actuation of the corresponding emergency condition detecting element, and means controlling application of said recorded Warning speech signals to said second transducer and operable at will to reduce the volume thereof to a value materially below normal live voice volume.

l0. ln an emergency warning system, transducer means operable to convert voice electric signals into audible speech sounds, recorded emergency speech reproducing means selectively operable to convert into voice electric signals any of a plurality of emergency speeches having a predetermined order of relative priority for operating said transducer means thereby, a corresponding plurality of control elements operatively connected to said reproducing means `and individually actuatable in response to respectively different emergency conditions for selectively operating said reproducing means to reproduce any of said emergency speeches corresponding thereto, and priority transfer means operated by said control elements and in turn controlling selective operation of said reproducing means by said control elements for preventing operation of such speech reproducing means by any such control element having a priority lower than any other control element then actuated of relatively higher priority.

11. In an emergency warning system, an annunciating device operable to register any of a Vplurality of different warning signals one at a time, a corresponding plurality of control elements operatively connected to said annunciating device and individually actuatable in response to respectively different emergency conditions for selectively operating said annunciating device to register corresponding warning signals, and priority transfer means operated by said control elements and in turn controlling selective operation of said annunciating device by said control elements for preventing operation of said annunciating device by any such control element having a priority lower than any other control element then actuated of relatively higher priority.

l2. In combination with an emergency warning systern of the type comprising means operable in response to any of a plurality of emergency conditions to annunciate from voice recordings individual warning messages corresponding respectively to such conditions, wherein such warning conditions have a predetermined order of priority of importance, a'plurality of disabling means individually responsive to the respective emergency conditions and respectively operable thereby for disabling said annunciating means from annunciating any warning message of lower priority than that represented by any such disabling means so operated.

13. In combination with a Voice annunciator system of the type comprising means operable in response to any of a plurality of conditions to annunciate from voice recordings individual messages corresponding respectively to such conditions, wherein such conditions have a predetermined order of priority of importance, a plurality of disabling means individually responsive to the respective conditions and respectively operable thereby for disabling said annunciating means from annunciating any message of lower priority than that represented by any such disabling means so operated.

14. In combination with a signalling system of the type comprising means operable in response to any of a plurality of control conditions to produce individual signals corresponding respectively to such conditions, said means including transducer means producing said signals in a medium for direct human perception, wherein such conditions have a predetermined order of priority of importance, a plurality of disabling means individually responsive to the respective conditions and respectively l@ operable thereby for disabling said annunciating means from annunciating any individual signal of lower priority than that represented by any such disabling means so operated.

15, In combination with a voice communication system, means operable in response to any of a plurality of conditions to annunciate through said system from voice recordings individual messages corresponding respectively to such conditions, wherein such conditions have a predetermined order `of priority of importance, and a plurality of disabling means individually responsive to the respective conditions and respectively operable thereby for disabling said annunciating means from annunciating any message of lower priority than that represented by any such disabling means so operated.

References Cited in the file of this patent UNITED STATES PATENTS 2,098,133 Carnahan Nov. 2, 1937 2,191,971 Mountstephen Feb. 27, 1940 2,661,394 Munch Dec. 1, 1953 

